Scaling Graphics (Fractal)

14 Feb 2006 6:26 AM

placid

Hi all,

This is the following code i have,

Public Class Form1
    Inherits System.Windows.Forms.Form

    Dim A, B, c, U, x, y As Double
    Dim Red, Green, Blue As Integer

    'Bitmap holds picture of the form
    Private b1 As Bitmap

    'Graphics object (printing buffer)
    Private g1 As Graphics

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As
Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form
Designer
    'It can be modified using the Windows Form Designer.
    'Do not modify it using the code editor.
    Friend WithEvents Timer1 As System.Windows.Forms.Timer
    Friend WithEvents tmrColor As System.Windows.Forms.Timer
    <System.Diagnostics.DebuggerStepThrough()> Private Sub
InitializeComponent()
        Me.components = New System.ComponentModel.Container
        Me.Timer1 = New System.Windows.Forms.Timer(Me.components)
        Me.tmrColor = New System.Windows.Forms.Timer(Me.components)
        '
        'Timer1
        '
        Me.Timer1.Enabled = True
        Me.Timer1.Interval = 1
        '
        'tmrColor
        '
        Me.tmrColor.Enabled = True
        Me.tmrColor.Interval = 1000
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.BackColor = System.Drawing.Color.Black
        Me.ClientSize = New System.Drawing.Size(292, 266)
        Me.Name = "Form1"
        Me.Text = "Form1"

    End Sub

#End Region

    Private Sub Form1_Activated(ByVal sender As Object, _
       ByVal e As System.EventArgs) Handles MyBase.Activated

        Static done As Boolean = False

        If Not done Then
            'Size and describe the form
            Me.Size = New Size(1000, 1000)
            Me.Text = "Mira Dust Fractal"

            'Create the initial bitmap from Form
            b1 = New Bitmap(Width, Height, Me.CreateGraphics())

            'Create the Graphics Object buffer
            ' which ties the bitmap to it so that
            ' when you draw something on the object
            ' the bitmap is updated
            g1 = Graphics.FromImage(b1)

            'Prevent reentry to initialization
            done = True

            A = 0.9
            B = 0.9998
            c = -0.234
            x = 950 : y = 950 'Starting Point

            Red = Green = Blue = 1

        End If
    End Sub

    Private Sub Form1_Paint(ByVal sender As Object, _
           ByVal e As System.Windows.Forms.PaintEventArgs) _
           Handles MyBase.Paint

        'Copy the bitmap to the form
        e.Graphics.DrawImage(b1, 0, 0)
    End Sub

    Private Sub rnd_dots()
        Dim C, Z, W As Double

        W = (System.Math.Cos(((A * x * x) + (C + (x * x))) / ((100 +
(x)))))
        Z = x

        U = (x * x)

        x = ((B * y + W))

        W = (System.Math.Sin((A * x) + ((C * U)) / (1 + U)))
        y = (W - Z)

        Dim p As Pen
        If (Red > 257) Then
            Red = 1
        Else
            Red = Red + 1
        End If

        Dim cl As Color =
System.Drawing.ColorTranslator.FromOle(RGB(Red, Blue, Green))

        p = New Pen(cl)

        g1.ScaleTransform(-1, 1)

        Dim r As Rectangle = New Rectangle(x, y, 1, 1)
        g1.DrawEllipse(p, r)

        'Copy the bitmap to the form
        Me.CreateGraphics.DrawImage(b1, 0, 0)

    End Sub

    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Timer1.Tick
        rnd_dots()
    End Sub

End Class

when i run this the fractal generated is too big, i.e it goes out the
boundary of the Form.

I remember with VB6 there was Form1.Scale(x1,y1)-(x2,y2) but so far i
have found no equivalent to this in VB.NET.

Could any one please help me with this problem. i want to be able to
scale a part of the fractal so that the other parts are not generated!

Please keep in mind im new to VB.NET!

thanks in advance

14 Feb 2006 10:09 AM

Armin Zingler

"placid" <Bul***@gmail.com> schrieb
> I remember with VB6 there was Form1.Scale(x1,y1)-(x2,y2) but so far
> i have found no equivalent to this in VB.NET.

http://msdn.microsoft.com/library/en-us/cpguide/html/_gdiplus_coordinate_systems_and_transformations_about.asp

Armin